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| author |   Reiji Watanabe <reijiw@google.com> | 2022-03-28 20:19:23 -0700 |
|---|---|---|
| committer |   Marc Zyngier <maz@kernel.org> | 2022-04-06 12:29:45 +0100 |
| commit | 26bf74bd9f6ff0f1545b4f0c92a37c232d076014 (patch) | |
| tree | 759d1aa56c57f78817cca50264eb2ddd015dc941 /arch/arm64/include/asm/kvm_emulate.h | |
| parent | KVM: arm64: vgic: Remove unnecessary type castings (diff) | |
| download | linux-dev-26bf74bd9f6ff0f1545b4f0c92a37c232d076014.tar.xz linux-dev-26bf74bd9f6ff0f1545b4f0c92a37c232d076014.zip | |
KVM: arm64: mixed-width check should be skipped for uninitialized vCPUs
KVM allows userspace to configure either all EL1 32bit or 64bit vCPUs
for a guest. At vCPU reset, vcpu_allowed_register_width() checks
if the vcpu's register width is consistent with all other vCPUs'.
Since the checking is done even against vCPUs that are not initialized
(KVM_ARM_VCPU_INIT has not been done) yet, the uninitialized vCPUs
are erroneously treated as 64bit vCPU, which causes the function to
incorrectly detect a mixed-width VM.
Introduce KVM_ARCH_FLAG_EL1_32BIT and KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED
bits for kvm->arch.flags. A value of the EL1_32BIT bit indicates that
the guest needs to be configured with all 32bit or 64bit vCPUs, and
a value of the REG_WIDTH_CONFIGURED bit indicates if a value of the
EL1_32BIT bit is valid (already set up). Values in those bits are set at
the first KVM_ARM_VCPU_INIT for the guest based on KVM_ARM_VCPU_EL1_32BIT
configuration for the vCPU.
Check vcpu's register width against those new bits at the vcpu's
KVM_ARM_VCPU_INIT (instead of against other vCPUs' register width).
Fixes: 66e94d5cafd4 ("KVM: arm64: Prevent mixed-width VM creation")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220329031924.619453-2-reijiw@google.com
Diffstat (limited to 'arch/arm64/include/asm/kvm_emulate.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_emulate.h | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index d62405ce3e6d..7496deab025a 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -43,10 +43,22 @@ void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr); void kvm_vcpu_wfi(struct kvm_vcpu *vcpu); +#if defined(__KVM_VHE_HYPERVISOR__) || defined(__KVM_NVHE_HYPERVISOR__) static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu) { return !(vcpu->arch.hcr_el2 & HCR_RW); } +#else +static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = vcpu->kvm; + + WARN_ON_ONCE(!test_bit(KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED, + &kvm->arch.flags)); + + return test_bit(KVM_ARCH_FLAG_EL1_32BIT, &kvm->arch.flags); +} +#endif static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu) { @@ -72,15 +84,14 @@ static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu) vcpu->arch.hcr_el2 |= HCR_TVM; } - if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) + if (vcpu_el1_is_32bit(vcpu)) vcpu->arch.hcr_el2 &= ~HCR_RW; - - /* - * TID3: trap feature register accesses that we virtualise. - * For now this is conditional, since no AArch32 feature regs - * are currently virtualised. - */ - if (!vcpu_el1_is_32bit(vcpu)) + else + /* + * TID3: trap feature register accesses that we virtualise. + * For now this is conditional, since no AArch32 feature regs + * are currently virtualised. + */ vcpu->arch.hcr_el2 |= HCR_TID3; if (cpus_have_const_cap(ARM64_MISMATCHED_CACHE_TYPE) || |